M-shaped antenna apparatus provided with at least two M-shaped antenna elements

Abstract

An M-shaped antenna apparatus includes at least two M-shaped antenna elements, a grounding conductor, and a feeding portion. At least two M-shaped antenna elements includes first and second M-shaped antenna elements respectively having first and second resonance frequencies. The first M-shaped antenna element includes a first transmission conductor; a first radiation conductor connected between one end of the first transmission conductor and the grounding conductor; a second radiation conductor connected between a middle portion of the first transmission conductor and the feeding portion; and a third radiation conductor connected between the other end of the first transmission conductor and the grounding conductor. The second M-shaped antenna element includes a second transmission conductor, a fourth radiation conductor, a fifth radiation conductor, and a sixth radiation conductor in a manner similar to that of the first M-shaped antenna element.

Description

[0001] 1. Field of the Invention[0002] The present invention relates to an M-shaped antenna apparatus, and in particular, to an M-shaped antenna apparatus provided with at least two M-shaped antennas.[0003] 2. Description of the Related Art[0004] FIG. 24 is a perspective view showing a construction of a prior art antenna apparatus capable of operating at a plurality of frequencies, and FIG. 25 is an enlarged plan view showing a detailed construction of an antenna element 113 and its peripheries of FIG. 24.[0005] Referring to FIG. 24, the prior art antenna apparatus has a rectangular equipment body which is constituted by a grounding conductor 111 provided on a bottom surface located on an X-Y plane, three rectangular top surface conductors 115a, 115b and 115c provided on a top surface and four side surface conductors 114. On the top surface thereof, a rectangular aperture 116 is formed between the top surface conductor 115a located in an approximate center portion and the top surfac...

AI Technical Summary

Benefits of technology

[0021] Accordingly, an essential object of the present invention is to solve the aforementioned problems and provide a compact light-weight antenna apparatus, having a plurality of resonance frequencies with a design simpler than that of the prior art examples and is capable of obtaining a bilateral directivity characteristic.

Problems solved by technology

However, the prior art antenna apparatus shown in FIG. 24 has had the problems as follows.

Accordingly, in this case, it has been inevitable to admit that the prior art structure, which has been unable to freely easily select a plurality of resonance frequencies, has been improper.

However, when the shape of the antenna apparatus is a rectangular or another polygonal shape, there are limitations on the direction in which the antenna is installed since the texture of the ceiling surface or the shape of the room are fixed.

If the impedance matching state is deteriorated as described above, then the electric power supplied to the M-shaped antenna elements 1 and 2 of the M-shaped antenna apparatus decreases to disadvantageously reduce the radiation efficiency of the antenna apparatus.

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